Panel: Next Mars rover should gather rocks, soil

This photo released by NASA shows a view of Mars that was stitched together by images taken by NASA's Viking Orbiter spacecraft. The space agency is planning to send a spacecraft similar to the Curiosity rover to the red planet in 2020. A NASA-appointed team released a report on Tuesday, July 9, 2013 that described the mission's science goals. (AP Photo/NASA)

To save money, engineers will dust off Curiosity's blueprints and reuse spare parts where possible. There are also plans to recycle the landing technology that delivered the car-size rover to the surface.

The future rover would build on discoveries of past Mars missions. Spirit and Opportunity, launched in 2004, uncovered plenty of geologic evidence of past water. Curiosity found a habitable environment where microbes could thrive and recently began a long road trip toward a mountain.

Scientists want Curiosity's successor to carry high-tech instruments that can peer at rocks on a microscopic level in search of chemical clues that might have been left behind by microbes, if they existed.

Since the Martian surface is a harsh environment with no signs of water, the panel said it didn't make sense to look for current life.

That would be a "foolish investment," said Brown University planetary geologist John Mustard, who headed the NASA-appointed team.

The only time NASA tackled the life question head-on was during the Viking missions of 1976. The twin spacecraft's rudimentary experiments failed to turn up signs of life. Many Mars researchers believe that question can be best answered by examining Martian rocks and dirt under a microscope on Earth.